Program to wish unknown users happy birthday

birthday.asm

; Program to wish an unknown user a happy birthday

section .text
	global _start

_start:
	; write
	mov eax, 4
	mov ebx, 1 ;std_out
	mov ecx, msg
	mov edx, msg_len
	int 0x80

	; get input from keyboard
	mov eax, 3
	mov ebx, 0 ;std_in
	mov ecx, user
	mov edx, 5
	int 0x80

	; output
	mov eax, 4
	mov ebx, 1
	mov ecx, res
	mov edx, res_len
	int 0x80

	; output
	mov eax, 4
	mov ebx, 1
	mov ecx, [user]
	mov edx, 5
	int 0x80

	exit:
		mov eax, 1
		int 0x80

section .bss
	user resw 5

section .data
	msg db "Enter celebrant's name: "
	msg_len equ $ - msg

	res db "Happy birthday, "
	res_len equ $ - msg